1. Field of the Invention
The present invention relates to a probe structure, and more particularly, to a micro probe structure which can be applied to a high-frequency and high-speed chip testing apparatus, and also can provide an elastic property for vertical deformation to maintain good contact during the testing condition.
2. Description of the Prior Art
The probe card is mainly utilized in testing wafer dies. The probe card uses a plurality of probes to contact the wafer die and with the associated test apparatus and the control of software, the testing of wafer dies is executed to screen out defective products which can be restored or discarded. Consequently, the subsequent packaging can be carried out and the yield of the products can be upgraded.
Along with the development of semiconductor technology and the miniaturization of the critical dimension of integrated circuits, the original cantilever probes, which have bending tips and are operated laterally, are gradually replaced by vertical probes with a smaller tip diameter and greater tip density. In terms of fabricating technology, the vertical probes can be classified into categories including: the spring-probes formed by mechanical processes, the probes with various geometric cross-section shapes formed by chemical etching, the multi-layered probes formed by micro-electrical-mechanical system (MEMS) processes, and the micro probes formed by Lithographie GaVanoformung Abformung (LIGA) processes. The LIGA process is, for example, represented in the Taiwan Patent number TWI284209 of the Industrial Technology Research Institute, “A METHOD OF FABRICATING VERTICAL PROBE HEAD.” Currently, various kinds of elastic bending structures are developed in the middle portion of the probes in a vertical probe card to attain vertical elastic properties when the probes are being contacted. Accordingly, the inventor is devoted to design an alternative probe structure.